1. Field of the Invention
This invention relates to various types of minimally-invasive inflatable balloon catheter designs and methods incorporating some type of means (e.g., a microwave-radiating antenna) for generating therapeutic heat in diseased tissue of a patient, and, more particularly, to catheter designs having an integrated structure that are capable of treating sub-cutaneous diseased tissue, such as (1) deep-seated tumors and (2) varicose veins.
2. Description of the Prior Art
Incorporated herein by reference is U.S. Pat. No. 5,007,437, entitled “Catheters for Treating Prostate Disease,” which issued to Fred Sterzer on Apr. 16, 1991 and is assigned to the same assignee as the present application. Briefly, U.S. Pat. No. 5,007,437 discloses that applying squeezing pressure to a diseased prostate, by means of a urethral and/or rectal catheter incorporating an inflatable prostate balloon, to compress the prostate while it is being irradiated from a microwave antenna, increases the therapeutic temperature to which the prostate tissue more distal to the microwave antenna can be heated without heating any non-prostate tissue beyond a maximum safe temperature, and reduces the temperature differential between the heated more distal and more proximate prostate tissue from the microwave antenna.
Further, incorporated herein by reference is Chapter Four (pages 105-120) of the publication New Frontiers in Medical Device Technology, edited by Rosen et al. and published by John Wiley & Sons, Inc. in 1995. This Chapter Four, which is authored by Fred Sterzer and is entitled “Localized Heating of Deep-Seated Tissues Using Microwave Balloon Catheters,” discloses, on pages 110 and 111, in vitro experiments which show that simultaneous ballooning and microwave heating to a 45° C. of an animal vessel resulted in the vessel becoming stiff with a wide-open lumen, becoming, in effect, a “biological stent.” Further, Chapter Four discloses, on page 117, that the temperatures produced inside the treated prostate can be non-invasively measured with a microwave radiometer and, on page 118, that with microwave balloon catheters it is possible to produce high therapeutic temperatures throughout the prostate gland without causing burning of tissues and to produce “biological stents” in the urethra in a single treatment session. In this regard, reference is made to U.S. Pat. No. 5,149,198, which issued to Sterzer on Sep. 22, 1992, and U.S. Pat. No. 5,688,050, which issued to Sterzer et al. on Nov. 18, 1997, which patents are directed to radiometers which may be used for measuring the temperature of a patient's body tissue. Finally, Chapter Four concludes, on pages 118 and 119, that potential applications for microwave balloon catheters include the production of “biological stents” in partially obstructed vessels or in the urethra.
Also, incorporated herein by reference is U.S. Pat. No. 5,992,419, entitled “Method Employing a Tissue-Heating Balloon Catheter to Produce a ‘Biological Stent’ in an Orifice or Vessel of a Patient's Body”, which issued to Fred Sterzer et al. on Nov. 30, 1999, and is assigned to the same assignee as the present application. This method makes use of a tissue-heating balloon catheter for creating “biological stents” that permanently widen the bore of an orifice or vessel of a patient's body and, more particularly, to the preferred use of a microwave balloon catheter for permanently widening the bore of the urethra of a male patient suffering from a disease of the prostate (such as benign prostatic hypertrophy (BPH) or prostate cancer) which results in an enlarged prostate that causes the bore of the urethra be narrowed.
In addition, incorporated herein by reference is U.S. Pat. No. 6,230,060, entitled “Single Integrated Structural Unit for Catheter Incorporating a Microwave Antenna”, which issued to Daniel D. Mawhinney on May 8, 2001, and is assigned to the same assignee as the present application. The tissue-heating balloon catheter designs disclosed is the aforesaid U.S. Pat. Nos. 5,007,437 and 5,992,419, involves the use of a urethral catheter with an inflatable balloon section to stretch the opening in the enlarged prostate and a radiating antenna section, that is spatially completely separate from and unconnected to the inflatable balloon section, to apply microwave energy to the stretched prostatic urethra with the objective, in the case of U.S. Pat. No. 5,992,419, of forming a long-lasting biological stent to relieve the symptoms of the affliction. The use of a separate antenna or applicator which must be inserted into the catheter forces several design compromises on both the catheter and the antenna, which are avoided in the case of the single integrated structural unit disclosed in U.S. Pat. No. 6,230,060.
Finally, the aforesaid Chapter Four of the publication New Frontiers in Medical Device Technology, on page 116, suggests the use of a catheter with a deflated balloon at its tip inserted into a large tumor volume to be heated by either radioactive seeds or a microwave antenna. Also, the News and Perspective article “Vanquishing Varicose Veins” appearing in Health News/June 2002 discloses a non-balloon catheter for use in applying either radio-frequency (RF) or laser energy in less-invasive treatments of varicose veins.